<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script>
        var str = '原始字符串：'
        // 1.检测字符串的长度
        console.log('字符串的长度：' + str.length);
        //2 字符串的拼接 + 
        console.log('沙漠' + '骆驼');
        console.log('沙漠' + 18);
    </script>
</head>
<body>
    

</body>
</html>